Female pampas grass.
Erianthus ravennae is considered hardy pamapas grass (to zone 4) but its plumes aren't as thick as the pampass grass hardy to zone 7.
The dwarf pampas grass is hardier, Cortaderia selloana ‘Pumila,' hardy to zone 6 and semi-hardy to zone 5.
Most propagated pampass is female; males don't have as full and silky plumes.
https://www.gardeningknowhow.com/ornamental/foliage/pampas-grass/growing-pampas-grass.htm
https://www.gardeningknowhow.com/ornamental/foliage/ravenna-grass/ravenna-grass-information.htm
Last year my large pampas grass had white/cream flowing flower - this year they are pink. How is this possible
There tends to be two main colors- Light pink, and dark pink. Some pinks are so light that they look white. This is subject to change throughout time with growing conditions and care. Generally, more color means it is healthy, and well cared for.
If you start noticing a pronounced, dark pink, then you may be seeing cross pollination with another species nearby, leaving the new seeds with some color once they flower.
here is an article that will help you to care for the grass: https://www.gardeningknowhow.com/ornamental/foliage/pampas-grass/growing-pampas-grass.htm
I have sections of dug-up pampas that I'd like to keep until Spring to plant in zone 5B. Is there a way to keep it without planting it & having to dig it up again? Clumps are about 1'X 2'
You can pot them up in potting soil. Then keep them in a frost free but cool area where you can water them well about once a month. Or, after potting them, "heel" them into the ground to give them winter protection.
https://www.gardeningknowhow.com/garden-how-to/info/heeling-in-plants.htm
Pampas grass is 25 years old, used initially to hide electrical boxes in yard, but have expanded to a large circle now, overtaking the yard and a porch railing.
You have a huge job ahead of you as Pampas grass puts down an extensive root system. Plus, the leaves are tough and razor-sharp. So be sure to wear gloves, long sleeves and long pants.
I would use a chain saw to cut it all back. Then if you have a strong shovel, start digging out sections all around till it is the size you want. If the clump was smaller, you could dig the whole clump and divide it with a saw. But if yours is 25 years old and taking over, I doubt you can dig the whole clump easily.
I also included instructions if you want to remove it entirely.
https://www.gardeningknowhow.com/ornamental/foliage/pampas-grass/pruning-pampas-grass.htm
https://www.gardeningknowhow.com/ornamental/foliage/pampas-grass/pampas-grass-removal.htm
that time. Is there a reason for this? It's grown huge but never flowered.
This can have a few causes, but the main few are as follows:
Too much nitrogen in the soil, or not enough phosphorus and potassium will halt flowering. You can offset by adding phosphorus and potassium.
Sometimes, improper pruning, or pruning at the wrong time can cause this, as well. They are best pruned in Spring when new growth begins.
This article will help you to care for the grass: https://www.gardeningknowhow.com/ornamental/foliage/pampas-grass/growing-pampas-grass.htm
This will help you to prune: https://www.gardeningknowhow.com/ornamental/foliage/pampas-grass/pruning-pampas-grass.htm
Here is an article that will offer more information on lack of plumage in ornamental grasses: https://www.gardeningknowhow.com/ornamental/foliage/ornamental-grass/no-plumes-on-ornamental-grass.htm
My pampas grass is about 5 years old and it has never flowered. It's supposed to be pink; last year I cut it right back and now it's enormous, but still no plumes.
It may be due to timing of pruning! These must be pruned in Spring, right as the grass starts to grow back. Pruning in winter will take away all protection of the plant.
If you have pruned right as new growth is coming back out, then it could be due to the nutrients present in the soil. Too much nitrogen, and not enough phosphorus and potassium will halt flowering, while producing an abundance of foliage. You can test your soil to find out what is missing, or what has just a little too much present.
This article will help: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/testing-soil.htm
These articles will help you to troubleshoot your flowering issue further: https://www.gardeningknowhow.com/ornamental/foliage/pampas-grass/growing-pampas-grass.htm
https://www.gardeningknowhow.com/ornamental/foliage/pampas-grass/pruning-pampas-grass.htm
I have been give some pampas grass plumes some of which aren't quite open yet. What can I do so they will open fully?
Once they are cut from the plant, they will not open much more than they are now. The only way is to allow them to fully mature on the plant before harvesting.
You could try putting them in a vase of water just ot see if that helps.